If you've read all the posts on the previous pages, and the only unread posts are on the last page, it
should show as read, once you go to the last page only. If it still shows as not read, that generally means that there were a few on the previous page that you skipped.
If it's one of those horrendous 58-page threads, or an ancient thread and you only want to read the current additions, once you're on the thread you can click on "thread options" on the left near the top and click "mark thread as read." Then it will only flag for any additional posts.
I try to read all the posts, but when it gets away from me, as it frequently does, I go to the forum page (for Credit Cards, or General Credit, etc.) and click on "Board Options," and then click "Mark all messages as read." That zeroes out the entire individual forum, and then I can start all over again.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007